Semiconductor Energy Laboratory Co., Ltd.

Suzunosuke Hiraishi

Shunpei Yamazaki

Junichi Koezuka

Yukinori Shima

Junichiro Sakata

Kengo Akimoto

Toshimitsu Obonai

Kenichi Okazaki

Miyuki Hosoba

Masahiko Hayakawa

Tatsuya Honda

Yasuharu Hosaka

Takashi Hamochi

Hiroshi Kanemura

Akiharu Miyanaga

Masashi Tsubuku

Hiromichi Godo

Takayuki Inoue

Erumu Kikuchi

Masami Jintyou

Kosei Noda

Ryosuke Watanabe

Shuhei Yoshitomi

Koki Inoue

Masashi Oota

Disclosed is a semiconductor device comprising a thin film transistor and wirings connected to the thin film transistor, in which the thin film transistor has a channel formation region in an oxide semiconductor layer, and a copper metal is used for at least one of a gate electrode, a source electrode, a drain electrode, a gate wiring, a source wiring, and a drain wiring. The extremely low off current of the transistor with the oxide semiconductor layer contributes to reduction in power consumption of the semiconductor device. Additionally, the use of the copper metal allows the combination of the semiconductor device with a display element to provide a display device with high display quality and negligible defects, which results from the low electrical resistance of the wirings and electrodes formed with the copper metal.

Semiconductor device comprising first and second conductive layers

Method for manufacturing semiconductor device

To reduce defects in an oxide semiconductor film in a semiconductor device. To improve electrical characteristics of and reliability in the semiconductor device including an oxide semiconductor film. A method for manufacturing a semiconductor device includes the steps of forming a gate electrode and a gate insulating film over a substrate, forming an oxide semiconductor film over the gate insulating film, forming a pair of electrodes over the oxide semiconductor film, forming a first oxide insulating film over the oxide semiconductor film and the pair of electrodes by a plasma CVD method in which a film formation temperature is 280° C. or higher and 400° C. or lower, forming a second oxide insulating film over the first oxide insulating film, and performing heat treatment at a temperature of 150° C. to 400° C. inclusive, preferably 300° C. to 400° C. inclusive, further preferably 320° C. to 370° C. inclusive.

To suppress a change in electrical characteristics and to improve reliability in a semiconductor device using a transistor including an oxide semiconductor. The semiconductor device includes a gate electrode over an insulating surface, an oxide semiconductor film overlapping with the gate electrode, a gate insulating film which is between the gate electrode and the oxide semiconductor film and is in contact with a surface of the oxide semiconductor film, a protective film in contact with an opposite surface of the surface of the oxide semiconductor film, and a pair of electrodes in contact with the oxide semiconductor film. In the gate insulating film or the protective film, the amount of gas having a mass-to-charge ratio m/z of 17 released by heat treatment is greater than the amount of nitrogen oxide released by heat treatment.

Semiconductor device

To reduce defects in an oxide semiconductor film in a semiconductor device. To improve electrical characteristics of and reliability in the semiconductor device including an oxide semiconductor film. A method for manufacturing a semiconductor device includes the steps of forming a gate electrode and a gate insulating film over a substrate, forming an oxide semiconductor film over the gate insulating film, forming a pair of electrodes over the oxide semiconductor film, forming a first oxide insulating film over the oxide semiconductor film and the pair of electrodes by a plasma CVD method in which a film formation temperature is 280&#xb0; C. or higher and 400&#xb0; C. or lower, forming a second oxide insulating film over the first oxide insulating film, and performing heat treatment at a temperature of 150&#xb0; C. to 400&#xb0; C. inclusive, preferably 300&#xb0; C. to 400&#xb0; C. inclusive, further preferably 320&#xb0; C. to 370&#xb0; C. inclusive.

Semiconductor device and display device

In a semiconductor element including an oxide semiconductor film as an active layer, stable electrical characteristics are achieved. A semiconductor element includes a base film which is an oxide film at least a surface of which has crystallinity; an oxide semiconductor film having crystallinity over the base film; a gate insulating film over the oxide semiconductor film; a gate electrode overlapping with at least the oxide semiconductor film, over the gate insulating film; and a source electrode and a drain electrode which are electrically connected to the oxide semiconductor film. The base film is a film containing indium and zinc. With the structure, a state of crystals in the oxide semiconductor film reflects that in the base film; thus, the oxide semiconductor film can have crystallinity in a large region in the thickness direction. Accordingly, the electrical characteristics of the semiconductor element including the film can be made stable.

Semiconductor element, method for manufacturing semiconductor element, and semiconductor device including semiconductor element

An object is, in a thin film transistor including an oxide semiconductor layer, to reduce contact resistance between the oxide semiconductor layer and source and drain electrode layers electrically connected to the oxide semiconductor layer. The source and drain electrode layers have a stacked-layer structure of two or more layers in which a layer in contact with the oxide semiconductor layer is formed using a metal whose work function is lower than the work function of the oxide semiconductor layer or an alloy containing such a metal. Layers other than the layer in contact with the oxide semiconductor layer of the source and drain electrode layers are formed using an element selected from Al, Cr, Cu, Ta, Ti, Mo, or W, an alloy containing any of these elements as a component, an alloy containing any of these elements in combination, or the like.

One embodiment of the present invention is a semiconductor device at least including an oxide semiconductor film, a gate insulating film in contact with the oxide semiconductor film, and a gate electrode overlapping with the oxide semiconductor film with the gate insulating film therebetween. The oxide semiconductor film has a spin density lower than 9.3&#xd7;10spins/cmand a carrier density lower than 1&#xd7;10/cm. The spin density is calculated from a peak of a signal detected at a g value (g) of around 1.93 by electron spin resonance spectroscopy. The oxide semiconductor film is formed by a sputtering method while bias power is supplied to the substrate side and self-bias voltage is controlled, and then subjected to heat treatment.

Semiconductor device, method for manufacturing semiconductor device, and method for forming oxide film

To suppress change in electric characteristics and improve reliability of a semiconductor device including a transistor formed using an oxide semiconductor. A semiconductor device includes a transistor including a gate electrode, a first insulating film, an oxide semiconductor film, a second insulating film, and a pair of electrodes. The gate electrode and the oxide semiconductor film overlap with each other. The oxide semiconductor film is located between the first insulating film and the second insulating film and in contact with the pair of electrodes. The first insulating film is located between the gate electrode and the oxide semiconductor film. An etching rate of a region of at least one of the first insulating film and the second insulating film is higher than 8 nm/min when etching is performed using a hydrofluoric acid.

Semiconductor device, display device, input/output device, and electronic device

Growing community of inventors

Tochigi, Japan

Suzunosuke Hiraishi